Page 75 - World of Animals - Book of Sharks & Ocean Predators

Killer whales
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Sharp senses

Orcas use echolocation as a means of
navigation, hunting and communication, by
emitting high-frequency clicks under the water

Emitting clicks
The orca emits short pulses
of sounds called clicks and
when these sound waves
connect with an object, they
bounce back.

In communication
Orcas also use echolocation
to communicate and each
pod has its own unique
sound that it uses when
members interact.

Making sound waves
Sound travels faster and
farther underwater than
it does in air, but the killer
whale’s sensory system
enables it to decipher the
diff erent echoes.

Listening for echoes
These echoes enable
the killer whale to
detect prey, but some
fish are able to hear the

clicks and escape with
early warning.

Orcas in numbers BELOW The
whales peek
above water to
-
15-18 530 thousand9.8 then jump at an
check for prey,
34 mph 90yrs Orca pods 50 227 impressive speed
A killer whale months to catch one
Age at which kilos
swimming at full The gestation Some female can consist of 15yrs
power can reach period for orca orcas can reach many members The estimated metres
this incredible mothers is twice this ripe old age hunting and population of The top length of female killer Amount an orca
top speed that of a human in the wild migrating as one killer whales a killer whale whales mature eats each day
of which can grow larger than three double-decker safer on the land than in the water. Working
buses! However, it’s not just a formidable body structure together, the whales duck under the surface and
– designed to propel them through the water at speeds swim side by side towards their quarry. At the
of 50 kilometres (30 miles) per hour – that enables orcas last moment, they quickly change direction and
to bring down such large prey. It’s their minds that make unleash an all-mighty wave that crashes over
them true killers. the block of ice and knocks the prey clean
Working as a team, orcas adopt a manoeuvre known as into the water.
spy-hopping, where the creatures swim vertically to the By now the seal is fully aware that it’s
surface and poke their heads above water to take a good under siege and there’s always a chance
look at their surroundings. For at least 30 seconds they it can escape by clambering aboard

use their tail (or fluke) for balance and pectoral fl ippers another ice floe. The orcas will be doing

on either side to keep afloat, like a human uses their arms everything they can to prevent this, by
to tread water. They’ll be hoping to spot a seal, although using their immense bodies to create
these cute-looking animals are armed with sharp claws underwater turbulence and blowing
and teeth – the killer whales know this, so will always aim bubbles to encourage the seal to dart
to grab the seal’s tail to be on the safe side. into open water where it doesn’t stand a
Before the chase even begins, the orcas gang up on the chance against the pod. From this point

seal that will be resting on an ice floe, thinking it’s probably on it’s a game of catch-the-seal-
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